C# Read XLSX File

Updated: August 2, 2026

To read XLSX files in C#, use IronXL's WorkBook.Load method to open Excel files and access worksheets to read cell data, perform calculations, and convert to DataTable or DataSet formats programmatically.

Quickstart: Load a workbook and access a worksheet effortlessly

With IronXL, you can load an XLSX file using the WorkBook.Load method in a single line. Then access its first or named worksheet instantly and begin reading cell values.

1Install IronXL with NuGet Package Manager
PM > Install-Package IronXL.Excel
```
Install-Package IronXL.Excel
```

2Copy and run this code snippet.

IronXL.WorkBook workbook = IronXL.WorkBook.Load("your-file.xlsx");

IronXL.WorkBook workbook = IronXL.WorkBook.Load("your-file.xlsx");

3Deploy to test on your live environment

Start using IronXL in your project today with a free trial

Read .XLSX Files C#

Get IronXL for your project
Load a WorkBook
Access data from a WorkSheet
Apply functions like Sum, Min, & Max
Read a WorkSheet as a DataTable, DataSet, and more

How Do I Get IronXL for My Project?

Use IronXL in your project for a simple way to work with Excel file formats in C#. You can either install IronXL via direct download or alternatively you can use NuGet Install for Visual Studio. The software is free for development.

PM > Install-Package IronXL.Excel

Install-Package IronXL.Excel

Before diving into reading XLSX files, explore the comprehensive IronXL documentation to understand all available features. IronXL supports both .xls and .xlsx formats, making it versatile for legacy and modern Excel files.

How to Tutorial

How Do I Load a WorkBook?

WorkBook is the class of IronXL whose object provides full access to the Excel file and all its functions. For example, to access an Excel file, use the code:

using IronXL;

// Load the workbook
WorkBook workBook = WorkBook.Load("sample.xlsx"); // Excel file path

using IronXL;

// Load the workbook
WorkBook workBook = WorkBook.Load("sample.xlsx"); // Excel file path

Imports IronXL

' Load the workbook
Dim workBook As WorkBook = WorkBook.Load("sample.xlsx") ' Excel file path

Imports IronXL

' Load the workbook
Dim workBook As WorkBook = WorkBook.Load("sample.xlsx") ' Excel file path

Why use the `WorkBook.Load()` method?

In the above code, the Load() function loads WorkBook into WorkBook. Any type of function can be performed on WorkBook by accessing the specific WorkSheet of an Excel file. The Load() method automatically detects the file format, whether it's XLS, XLSX, XLSM, XLTX, or CSV. For more advanced loading scenarios, check out the detailed guide on loading spreadsheets.

How Do I Access a Specific WorkSheet?

To access a specific WorkSheet of an Excel file, IronXL provides the WorkBook class. It can be used in several different ways:

What are the different ways to access a worksheet?

using IronXL;

// Access sheet by name
WorkSheet workSheet = workBook.GetWorkSheet("Sheet1");

using IronXL;

// Access sheet by name
WorkSheet workSheet = workBook.GetWorkSheet("Sheet1");

Imports IronXL

' Access sheet by name
Dim workSheet As WorkSheet = workBook.GetWorkSheet("Sheet1")

Imports IronXL

' Access sheet by name
Dim workSheet As WorkSheet = workBook.GetWorkSheet("Sheet1")

WorkBook["SheetName"] is the WorkSheet that is declared in the above portion.

WorkBook

using IronXL;

// Access sheet by index
WorkSheet workSheet = workBook.WorkSheets[0];

using IronXL;

// Access sheet by index
WorkSheet workSheet = workBook.WorkSheets[0];

Imports IronXL

' Access sheet by index
Dim workSheet As WorkSheet = workBook.WorkSheets(0)

Imports IronXL

' Access sheet by index
Dim workSheet As WorkSheet = workBook.WorkSheets(0)

WorkBook.Load()

using IronXL;

// Access the default worksheet
WorkSheet workSheet = workBook.DefaultWorkSheet;

using IronXL;

// Access the default worksheet
WorkSheet workSheet = workBook.DefaultWorkSheet;

Imports IronXL

' Access the default worksheet
Dim workSheet As WorkSheet = workBook.DefaultWorkSheet

Imports IronXL

' Access the default worksheet
Dim workSheet As WorkSheet = workBook.DefaultWorkSheet

sample.xlsx

using IronXL;
using System.Linq;

// Access the first worksheet
WorkSheet workSheet = workBook.WorkSheets.First();

using IronXL;
using System.Linq;

// Access the first worksheet
WorkSheet workSheet = workBook.WorkSheets.First();

Imports IronXL
Imports System.Linq

' Access the first worksheet
Dim workSheet As WorkSheet = workBook.WorkSheets.First()

Imports IronXL
Imports System.Linq

' Access the first worksheet
Dim workSheet As WorkSheet = workBook.WorkSheets.First()

workBook

using IronXL;
using System.Linq;

// Access the first or default worksheet
WorkSheet workSheet = workBook.WorkSheets.FirstOrDefault();

using IronXL;
using System.Linq;

// Access the first or default worksheet
WorkSheet workSheet = workBook.WorkSheets.FirstOrDefault();

Imports IronXL
Imports System.Linq

' Access the first or default worksheet
Dim workSheet As WorkSheet = workBook.WorkSheets.FirstOrDefault()

Imports IronXL
Imports System.Linq

' Access the first or default worksheet
Dim workSheet As WorkSheet = workBook.WorkSheets.FirstOrDefault()

workBook

WorkBook.Load

WorkSheet

workBook

WorkBook

When should I use each worksheet access method?

Each method has its ideal use case:

GetWorkSheet("name"): When you know the exact sheet name
WorkSheets[index]: For iterating through sheets programmatically
DefaultWorkSheet: Quick access when working with single-sheet files
First() or FirstOrDefault(): Safe options when sheet names might change

After getting ExcelSheet workSheet, you can get any type of data from it and perform all Excel functions on it. For more complex worksheet operations, refer to the guide on opening Excel worksheets in C#.

How Do I Access Data from a WorkSheet?

Data can be accessed from ExcelSheet workSheet with this process:

What data types can I read from cells?

using IronXL;

// Accessing data as a string
string dataString = workSheet["A1"].ToString();

// Accessing data as an integer
int dataInt = workSheet["B1"].Int32Value;

using IronXL;

// Accessing data as a string
string dataString = workSheet["A1"].ToString();

// Accessing data as an integer
int dataInt = workSheet["B1"].Int32Value;

Imports IronXL

' Accessing data as a string
Dim dataString As String = workSheet("A1").ToString()

' Accessing data as an integer
Dim dataInt As Integer = workSheet("B1").Int32Value

Imports IronXL

' Accessing data as a string
Dim dataString As String = workSheet("A1").ToString()

' Accessing data as an integer
Dim dataInt As Integer = workSheet("B1").Int32Value

IronXL provides various value accessors for different data types:

StringValue: For text data
Int32Value: For integers
DoubleValue: For decimals
DateTimeValue: For dates
BoolValue: For true/false values

How do I read multiple cells at once?

You can also get data from multiple cells of a specific column:

foreach (var cell in workSheet["A2:A10"])
{
    Console.WriteLine("Value is: {0}", cell.Text);
}

foreach (var cell in workSheet["A2:A10"])
{
    Console.WriteLine("Value is: {0}", cell.Text);
}

For Each cell In workSheet("A2:A10")
	Console.WriteLine("Value is: {0}", cell.Text)
Next cell

For Each cell In workSheet("A2:A10")
	Console.WriteLine("Value is: {0}", cell.Text)
Next cell

This displays the values from cell A2 to A10. For more advanced range selection techniques, visit the select range tutorial.

What does a complete implementation look like?

A complete code example of the specifics above is provided here:

using IronXL;
using System;

// Load an Excel file
WorkBook workBook = WorkBook.Load("sample.xlsx");
WorkSheet workSheet = workBook.GetWorkSheet("Sheet1");

// Specify the range
foreach (var cell in workSheet["B2:B10"])
{
    Console.WriteLine("Value is: {0}", cell.Text);
}

using IronXL;
using System;

// Load an Excel file
WorkBook workBook = WorkBook.Load("sample.xlsx");
WorkSheet workSheet = workBook.GetWorkSheet("Sheet1");

// Specify the range
foreach (var cell in workSheet["B2:B10"])
{
    Console.WriteLine("Value is: {0}", cell.Text);
}

Imports IronXL
Imports System

' Load an Excel file
Dim workBook As WorkBook = WorkBook.Load("sample.xlsx")
Dim workSheet As WorkSheet = workBook.GetWorkSheet("Sheet1")

' Specify the range
For Each cell In workSheet("B2:B10")
    Console.WriteLine("Value is: {0}", cell.Text)
Next

Imports IronXL
Imports System

' Load an Excel file
Dim workBook As WorkBook = WorkBook.Load("sample.xlsx")
Dim workSheet As WorkSheet = workBook.GetWorkSheet("Sheet1")

' Specify the range
For Each cell In workSheet("B2:B10")
    Console.WriteLine("Value is: {0}", cell.Text)
Next

It displays the following result:

Console output showing extracted worksheet data with Government, Private, Midmarket, and Channel Partners values

With the Excel file Sample.xlsx:

Excel spreadsheet with business data showing Segment, Country, Product, and Discount Band columns across 16 rows

These methodologies show how effortless it is to use Excel file data in your project. For practical examples of reading Excel files without Interop, explore the read Excel examples.

How Can I Perform Functions on Data?

Access filtered data from an Excel WorkSheet by applying aggregate functions like Sum, Min, or Max using the following code:

Which aggregate functions are available?

using IronXL;

// Apply aggregate functions
decimal sum = workSheet["G2:G10"].Sum(); // Sum of cells from G2 to G10
decimal min = workSheet["G2:G10"].Min(); // Minimum value in cells from G2 to G10
decimal max = workSheet["G2:G10"].Max(); // Maximum value in cells from G2 to G10

using IronXL;

// Apply aggregate functions
decimal sum = workSheet["G2:G10"].Sum(); // Sum of cells from G2 to G10
decimal min = workSheet["G2:G10"].Min(); // Minimum value in cells from G2 to G10
decimal max = workSheet["G2:G10"].Max(); // Maximum value in cells from G2 to G10

Imports IronXL

' Apply aggregate functions
Dim sum As Decimal = workSheet("G2:G10").Sum() ' Sum of cells from G2 to G10
Dim min As Decimal = workSheet("G2:G10").Min() ' Minimum value in cells from G2 to G10
Dim max As Decimal = workSheet("G2:G10").Max() ' Maximum value in cells from G2 to G10

Imports IronXL

' Apply aggregate functions
Dim sum As Decimal = workSheet("G2:G10").Sum() ' Sum of cells from G2 to G10
Dim min As Decimal = workSheet("G2:G10").Min() ' Minimum value in cells from G2 to G10
Dim max As Decimal = workSheet("G2:G10").Max() ' Maximum value in cells from G2 to G10

IronXL supports several aggregate methods you can call directly on a range, including:

Avg(): Calculate the mean value
Count(): Count non-empty cells
Sum(): Add all values
Min(): Find the smallest value
Max(): Find the largest value

For functions without a dedicated method - such as MEDIAN, COUNTIF, or STDEV - assign the corresponding Excel formula to a cell (for example, cell.Formula = "=MEDIAN(G2:G10)") and let IronXL evaluate it.

How do I implement multiple functions together?

For more details, check out our in-depth tutorial on How to Write C# Excel Files with specifics on aggregate functions. You can also explore the complete list of math functions available in IronXL.

using IronXL;
using System;

// Load the Excel workbook
WorkBook workBook = WorkBook.Load("sample.xlsx");

// Get the specified WorkSheet
WorkSheet workSheet = workBook.GetWorkSheet("Sheet1");

// Calculate sum, minimum, and maximum for a range of cells
decimal sum = workSheet["G2:G10"].Sum();
decimal min = workSheet["G2:G10"].Min();
decimal max = workSheet["G2:G10"].Max();

// Output results
Console.WriteLine("Sum is: {0}", sum);
Console.WriteLine("Min is: {0}", min);
Console.WriteLine("Max is: {0}", max);

using IronXL;
using System;

// Load the Excel workbook
WorkBook workBook = WorkBook.Load("sample.xlsx");

// Get the specified WorkSheet
WorkSheet workSheet = workBook.GetWorkSheet("Sheet1");

// Calculate sum, minimum, and maximum for a range of cells
decimal sum = workSheet["G2:G10"].Sum();
decimal min = workSheet["G2:G10"].Min();
decimal max = workSheet["G2:G10"].Max();

// Output results
Console.WriteLine("Sum is: {0}", sum);
Console.WriteLine("Min is: {0}", min);
Console.WriteLine("Max is: {0}", max);

Imports IronXL
Imports System

' Load the Excel workbook
Dim workBook As WorkBook = WorkBook.Load("sample.xlsx")

' Get the specified WorkSheet
Dim workSheet As WorkSheet = workBook.GetWorkSheet("Sheet1")

' Calculate sum, minimum, and maximum for a range of cells
Dim sum As Decimal = workSheet("G2:G10").Sum()
Dim min As Decimal = workSheet("G2:G10").Min()
Dim max As Decimal = workSheet("G2:G10").Max()

' Output results
Console.WriteLine("Sum is: {0}", sum)
Console.WriteLine("Min is: {0}", min)
Console.WriteLine("Max is: {0}", max)

Imports IronXL
Imports System

' Load the Excel workbook
Dim workBook As WorkBook = WorkBook.Load("sample.xlsx")

' Get the specified WorkSheet
Dim workSheet As WorkSheet = workBook.GetWorkSheet("Sheet1")

' Calculate sum, minimum, and maximum for a range of cells
Dim sum As Decimal = workSheet("G2:G10").Sum()
Dim min As Decimal = workSheet("G2:G10").Min()
Dim max As Decimal = workSheet("G2:G10").Max()

' Output results
Console.WriteLine("Sum is: {0}", sum)
Console.WriteLine("Min is: {0}", min)
Console.WriteLine("Max is: {0}", max)

This code displays the following output:

Terminal showing data analysis results: Sum=482, Min=12, Max=350 on black background

And this is how the Excel file Sample.xlsx looks:

Excel spreadsheet with sales data showing segments, countries, products, units sold, and pricing across multiple rows

How Do I Read Excel WorkSheet as DataTable?

Using IronXL, it is easy to work with an Excel WorkSheet as a DataTable. This feature is particularly useful when you need to integrate Excel data with existing data processing pipelines or bind data to UI controls.

What is the basic conversion method?

using IronXL;
using System.Data;

// Convert worksheet to DataTable
DataTable dt = workSheet.ToDataTable();

using IronXL;
using System.Data;

// Convert worksheet to DataTable
DataTable dt = workSheet.ToDataTable();

Imports IronXL
Imports System.Data

' Convert worksheet to DataTable
Dim dt As DataTable = workSheet.ToDataTable()

Imports IronXL
Imports System.Data

' Convert worksheet to DataTable
Dim dt As DataTable = workSheet.ToDataTable()

How do I use the first row as column headers?

To use the first row of ExcelSheet as DataTable ColumnName:

using IronXL;
using System.Data;

// Convert worksheet to DataTable with the first row as column names
DataTable dt = workSheet.ToDataTable(true);

using IronXL;
using System.Data;

// Convert worksheet to DataTable with the first row as column names
DataTable dt = workSheet.ToDataTable(true);

Imports IronXL
Imports System.Data

' Convert worksheet to DataTable with the first row as column names
Dim dt As DataTable = workSheet.ToDataTable(True)

Imports IronXL
Imports System.Data

' Convert worksheet to DataTable with the first row as column names
Dim dt As DataTable = workSheet.ToDataTable(True)

The Boolean parameter of ToDataTable() sets the first row as the column names of your DataTable. By default, its value is False. This is especially useful when working with structured data that includes headers.

How do I iterate through the DataTable?

using IronXL;
using System;
using System.Data;

// Load the Excel workbook
WorkBook workBook = WorkBook.Load("sample.xlsx");

// Get the specified WorkSheet
WorkSheet workSheet = workBook.GetWorkSheet("Sheet1");

// Convert WorkSheet to DataTable
DataTable dt = workSheet.ToDataTable(true); // Use first row as column names

// Iterate through rows and columns and display data
foreach (DataRow row in dt.Rows) // Access rows
{
    for (int i = 0; i < dt.Columns.Count; i++) // Access columns of corresponding row
    {
        Console.Write(row[i] + " ");
    }
    Console.WriteLine();
}

using IronXL;
using System;
using System.Data;

// Load the Excel workbook
WorkBook workBook = WorkBook.Load("sample.xlsx");

// Get the specified WorkSheet
WorkSheet workSheet = workBook.GetWorkSheet("Sheet1");

// Convert WorkSheet to DataTable
DataTable dt = workSheet.ToDataTable(true); // Use first row as column names

// Iterate through rows and columns and display data
foreach (DataRow row in dt.Rows) // Access rows
{
    for (int i = 0; i < dt.Columns.Count; i++) // Access columns of corresponding row
    {
        Console.Write(row[i] + " ");
    }
    Console.WriteLine();
}

Imports IronXL
Imports System
Imports System.Data

' Load the Excel workbook
Dim workBook As WorkBook = WorkBook.Load("sample.xlsx")

' Get the specified WorkSheet
Dim workSheet As WorkSheet = workBook.GetWorkSheet("Sheet1")

' Convert WorkSheet to DataTable
Dim dt As DataTable = workSheet.ToDataTable(True) ' Use first row as column names

' Iterate through rows and columns and display data
For Each row As DataRow In dt.Rows ' Access rows
    For i As Integer = 0 To dt.Columns.Count - 1 ' Access columns of corresponding row
        Console.Write(row(i) & " ")
    Next
    Console.WriteLine()
Next

Imports IronXL
Imports System
Imports System.Data

' Load the Excel workbook
Dim workBook As WorkBook = WorkBook.Load("sample.xlsx")

' Get the specified WorkSheet
Dim workSheet As WorkSheet = workBook.GetWorkSheet("Sheet1")

' Convert WorkSheet to DataTable
Dim dt As DataTable = workSheet.ToDataTable(True) ' Use first row as column names

' Iterate through rows and columns and display data
For Each row As DataRow In dt.Rows ' Access rows
    For i As Integer = 0 To dt.Columns.Count - 1 ' Access columns of corresponding row
        Console.Write(row(i) & " ")
    Next
    Console.WriteLine()
Next

Using the above code, every cell value of the WorkSheet can be accessed and used as required. For more advanced DataTable operations, see the guide on importing and exporting as DataSet.

How Do I Read Excel File as DataSet?

IronXL provides a simple function to use a complete Excel file (WorkBook) as a DataSet. Use the ToDataSet method to turn the whole workbook into DataSet.
In this example, we will see how to use the Excel file as a DataSet.

How do I convert a workbook to DataSet?

using IronXL;
using System;
using System.Data;

// Load the Excel workbook
WorkBook workBook = WorkBook.Load("sample.xlsx");

// Convert the WorkBook to a DataSet
DataSet ds = workBook.ToDataSet();

// Iterate through tables in the DataSet and display table names
foreach (DataTable dt in ds.Tables)
{
    Console.WriteLine(dt.TableName);
}

using IronXL;
using System;
using System.Data;

// Load the Excel workbook
WorkBook workBook = WorkBook.Load("sample.xlsx");

// Convert the WorkBook to a DataSet
DataSet ds = workBook.ToDataSet();

// Iterate through tables in the DataSet and display table names
foreach (DataTable dt in ds.Tables)
{
    Console.WriteLine(dt.TableName);
}

Imports IronXL
Imports System
Imports System.Data

' Load the Excel workbook
Dim workBook As WorkBook = WorkBook.Load("sample.xlsx")

' Convert the WorkBook to a DataSet
Dim ds As DataSet = workBook.ToDataSet()

' Iterate through tables in the DataSet and display table names
For Each dt As DataTable In ds.Tables
    Console.WriteLine(dt.TableName)
Next

Imports IronXL
Imports System
Imports System.Data

' Load the Excel workbook
Dim workBook As WorkBook = WorkBook.Load("sample.xlsx")

' Convert the WorkBook to a DataSet
Dim ds As DataSet = workBook.ToDataSet()

' Iterate through tables in the DataSet and display table names
For Each dt As DataTable In ds.Tables
    Console.WriteLine(dt.TableName)
Next

The output of the above code looks like this:

Corrupted or incomplete screenshot showing only Sheet1, Sheet2, Sheet3 labels

And the Excel file Sample.xlsx looks like this:

(center content omitted for brevity)

How do I access each cell value across all worksheets?

In the above example, we can easily parse an Excel file into a DataSet and work with every DataTable of an Excel file as a DataTable. Dive deeper into how to parse Excel as a DataSet here featuring code examples.

Let's see one more example of how to access each cell value of all ExcelSheets. Here, we can access each cell value of every ExcelSheet of an Excel file.

using IronXL;
using System;

// Load the Excel workbook
WorkBook workBook = WorkBook.Load("sample.xlsx");

// Iterate through every WorkSheet in the WorkBook
foreach (WorkSheet workSheet in workBook.WorkSheets)
{
    Console.WriteLine($"Worksheet: {workSheet.Name}");

    // Access each filled cell value on the current WorkSheet
    foreach (var cell in workSheet.FilledCells)
    {
        Console.WriteLine($"{cell.Address}: {cell.Text}");
    }
}

using IronXL;
using System;

// Load the Excel workbook
WorkBook workBook = WorkBook.Load("sample.xlsx");

// Iterate through every WorkSheet in the WorkBook
foreach (WorkSheet workSheet in workBook.WorkSheets)
{
    Console.WriteLine($"Worksheet: {workSheet.Name}");

    // Access each filled cell value on the current WorkSheet
    foreach (var cell in workSheet.FilledCells)
    {
        Console.WriteLine($"{cell.Address}: {cell.Text}");
    }
}

Using the above example, it is convenient to access each cell value of every ExcelSheet of an Excel file. This approach is particularly useful when dealing with multi-sheet workbooks where data is distributed across different tabs.

For more on how to Read Excel Files Without Interop check out the code here. The API reference documentation provides comprehensive details about all available methods and properties at the IronXL API Reference.

Tutorial Quick Access

API Reference for IronXL

Read more about IronXL's features, classes, method fields, namespaces, and enums in the documentation.

API Reference for IronXL

WorkSheet

Frequently Asked Questions

How can I read an XLSX file in C# using IronXL?

You can read an XLSX file in C# using IronXL by utilizing the `WorkBook.Load` method, which allows you to open the Excel file and access its worksheets to perform various operations.

What method do I use to access data from a specific worksheet in IronXL?

You can access data from a specific worksheet using several methods like `GetWorkSheet("name")`, `WorkSheets[index]`, `DefaultWorkSheet`, or using LINQ methods such as `First()` or `FirstOrDefault()`.

How do I convert an Excel worksheet to a DataTable using IronXL?

You can convert an Excel worksheet to a DataTable using the `ToDataTable` method, which can use the first row of the worksheet as column headers if specified.

How can I perform aggregate functions like Sum, Min, and Max with IronXL?

IronXL allows you to perform aggregate functions such as `Sum()`, `Min()`, and `Max()` directly on a range of cells, facilitating easy data analysis.

What are the benefits of using IronXL to read XLSX files in C#?

IronXL provides a simple API for reading XLSX files in C#, supporting a wide range of Excel formats and allowing for data manipulation and conversion without needing Excel Interop.

How do I handle different data types when accessing cell values with IronXL?

IronXL offers specific value accessors for different data types, like `StringValue` for text, `Int32Value` for integers, `DoubleValue` for decimals, and `DateTimeValue` for dates.

Can I convert an entire workbook to a DataSet with IronXL?

Yes, you can convert an entire workbook to a DataSet using the `ToDataSet` method, which allows you to work with each worksheet as a separate DataTable.

What is the recommended way to read multiple cells at once in IronXL?

You can read multiple cells by iterating over a specified range, for example, using `foreach` on `workSheet["A2:A10"]` to read each cell's value.

How do I install IronXL in my C# project?

You can install IronXL via direct download or through NuGet Package Manager in Visual Studio. The library is free for development purposes.

How can I display Excel sheet data results in the console using IronXL?

To display Excel sheet data in the console, load the workbook using `WorkBook.Load`, access the desired worksheet, and iterate through cells to output their values using `Console.WriteLine`.

Curtis Chau

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Technical Writer

Curtis Chau holds a Bachelor’s degree in Computer Science (Carleton University) and specializes in front-end development with expertise in Node.js, TypeScript, JavaScript, and React. Passionate about crafting intuitive and aesthetically pleasing user interfaces, Curtis enjoys working with modern frameworks and creating well-structured, visually appealing manuals.

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